SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '992628b0e07477143590efcb09a63b62c63e5eae97f87f993ddb5fe8bcfb1ea1' 
  AND token = 'CnvpHp0IxNzfSf2Xk0Hnd9UHjo/EgvOK9th7RTVKJo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}